Packaging setup: DMG distribution + proper log location

logback.xml: write to ~/Library/Logs/PhotoPhetch/ (standard macOS
app log location), rolling 7-day retention, 50MB cap. Console output
retained for development runs.

build.gradle.kts: fix packaging config — remove missing icon.icns
reference, add copyright, add signing block (disabled by default).

To build:
  ./gradlew packageDmg
  # Output: build/compose/binaries/main/dmg/PhotoPhetch-1.0.0.dmg

Logs viewable in Console.app or:
  tail -f ~/Library/Logs/PhotoPhetch/photophetch.log

build.gradle.kts

@@ -43,9 +43,14 @@ compose.desktop {
             packageVersion = "1.0.0"
             description = "Import photos from phones into PhotoPhile"
             vendor = "bolenpad"
+            copyright = "© 2026 Kyle Bolen"
             macOS {
                 bundleID = "com.bolenpad.photophetch"
-                iconFile.set(project.file("src/main/resources/icon.icns"))
+                // Uncomment and add icon.icns to src/main/resources/ for a custom icon:
+                // iconFile.set(project.file("src/main/resources/icon.icns"))
+                signing {
+                    sign.set(false)  // set true + add identity for App Store / Gatekeeper
+                }
             }
         }